Fuel injection system



R c. GROVES FUEL INJECTION SYSTEM Jul 21, 1959 Filed Feb. 4. 1957 Attorney ,July z1,19 59' m. GRQVES 2,895,461 I FUEL INJECTION SYSTEM FiledFeb. 4. 1957 s Sheets-sheaf? Inventor Attomey ,1 R. C.GROV E$ 2,895,463

FUEL- INJECTION SYSTEM Filed Feb, 4. 1957 5 Sheets-Sheet 3 IN VEN TOR.

A T TORNEY United ttes Patent FUEL INJECTION SYSTEM Ronald C. Groves, Rochester, N.Y., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application February 4, 1957, Serial No. 638,103 11 Claims. (Cl. 123-119) The present invention relates to charge forming means for an internal combustion engine and more particularly to means for injecting metered quantities of fuel into the charge.

In a spark ignited engine a combustible charge of air and fuel is normally formed outside of the cylinder and then introduced into the cylinder where it is compressed and ignited. Although there are numerous ways of mixing the fuel with the air, there are several advantages to be obtained by providing a fuel metering system which is responsive to the air flow into the engine and is adapted to inject metered quantities of fuel into the charge imme diately adjacent the intake valves so as to mix with the induction air.

It is now proposed to provide a fuel injection system which is simple and reliable in operation. More particularly, this is to be accomplished by providing a fuel metering mechanism which is responsive to the quantity of induction air and the fuel flow and includes means for maintaining the two in some predetermined proportion. The metered fuel is divided into equal increments which are delivered to the intake valves which include a pump integral therewith so that the opening movement of the intake valve will pump a metered quantity of fuel into the charge in timed relation to the flow thereof.

In the three sheets of drawings:

Figure l is a diagrammatic view of a portion of a fuel injection system embodying the present invention.

Figure 2 is a cross-sectional view of a fuel metering mechanism and the discharge means therefor.

Figure 3 is a cross-sectional view of a modified injection nozzle.

Figure 4 is a diagrammatic View of the distributing and nozzle portion of the injeciton system in Figure 1.

Referring to the drawings in more detail, the present invention may be embodied in charge forming means for an internal combustion engine having a cylinder block with a plurality of cylinders that extend therethrough and form openings in the face of the block. A cylinder head 12 is secured on the face and has a plurality of cavities 14 therein positioned to register with the ends of the cylinders and thereby form combustion chambers 16. A separate intake passage 18 for each combustion cham ber 16 extends transversely through the cylinder head 12. The inner ends of these passages 18 form intake valve seats 20 opening into the combustion chambers 16, while the outer ends thereof form intake ports in the side of the cylinder head. The flow of air into the combustion chamber 16 is controlled by intake valves 22 actuated by a camshaft.

In order to supply air to these passages 18 for charg ing the cylinders an induction system 24 is provided. The induction system 24 comprises an intake assembly 26 and a manifold for. interconnecting the intake assembly 26 with the various intake passages 18. In the present instance the assembly 26 comprises a housing 28 having a pair of parallel inlet passages 30 extending therethrough. Each of these passages includes a venturi 32 t with a restrictedthroat 34 and a throttle valve 36 disposed downstream thereof for regulating the volume of air flow therethrough. A choke valve 38 actuated by suitable temperature responsive means 40 may also be provided in the intake 26 for temporarily increasing the vacuum in the venturi throat 34.

In order to form a combustible charge of air and fuel, a fuel system 41 is provided that includes a fuel chamber 42, a fuel metering mechanism 44, a fuel jet unit 46, a distributor .48 and injection nozzles: 50. The fuel chamber 42has an inlet 52 connected with the outlet of a fuel pump and a vapor vent 54 in the top thereof that is controlled by a float valve 56 that will open and blow off any vapors that may collect in the fuel chamber 42.

The metering mechanism 44 comprises a cylindrical housing 58 having an air diaphragm 60 and a fuel diaphragm 62 disposed transversely thereof to form a pair of air chambers 64 and 66 and a pair of fuel chambers 68 and 70. These diaphragms 60 and 62 are rigidly interconnected with each other by a shaft 72 having a fuel metering valve 74 therein that is disposed in the fuel line 76 from the outlet of the fuel chamber 42. The fuel line 76 interconnects the fuel chamber 68' with the jet unit 46.

One of the air chambers 64 is vented to the atmosphere while the other air chamber 66 isinterconnected with the throat 34 of the venturi 32. As a result it will be seen that there will be a pressure differential across this diaphragm 60 that will produce a force on the shaft 72 indicative of the amount of air flow and tending to open the metering valve 74. One of the fuel chambers 68 is interconnected with the fuel line 76 anterior to the jet unit 46 while the other chamber 70 is interconnected with the fuel line 76 posterior to the jet unit 46. Since the jet unit 46 includes a plurality of calibrated metering restrictions 78, 80 and 82 through which the metered fuel must flow, there will be a pressure differential across the fuel diaphragm 62 that will produce a force on the shaft 72 indicative of the amount of fuel flowing through the jet unit. This force will oppose the force from the air diaphragm 60 and tend to close the metering valve 74. As a result it may be seen that the two forces will cause movement of the metering valve 74 until the two forces are equal and the air and fuel are in some predetermined ratio.

The air-fuel ratio will be determined by the hydraulic resistance of the jet unit 46. The present jet unit 46 includes an idling orifice 84, a road load or economy orifice 86 and a power enrichment orifice 88. The effective resistances of the idling androad load orifices 84 and 86 are controlled by movement of the throttle valves 36 whereas the power orifice is controlled by a valve 90 actuated by a diaphragm 92 responsive to the induction vacuum. It may be seen that by varying the areas of the orifices the resistance of the jetunit 46 will be varied during various operating conditions of the engine so that theainfuel ratio will vary to- .meet the fuel demands of the engine. Y

Thefuel line 76 fromoutlet 94 of the fuel jet unit 46 is connected to a suitable flow divider. such as a rotary fuel distributor 48. T he distributor 48 includes a rotor 98 driven from the engine camshaft and a plurality of injector lines 108 that radiate therefrom and are interconnected with fuel nozzles 50 for injecting metered fuel into the various intake passages 18.

Inthe present instance each of these nozzles 50 are incorporated into an intake valve 22 to be actuated in timed relation to the charging of the cylinders. A valve guide 104 is'pressed into .a passage 106 in the head 12 opening into the intake passage 18. The inner surface portion 112.

a a of the guide 104 has three cylindrical portions. The

lower portion 108 is a sliding fit on the valve stem 110 while the upper portion 112 is a sliding fit on a bushing 114 secured to the upper end of the valve stem 110. The middle portion 116 of the surface is of intermediate diameter and forms an annularchamber 11'8 around the valve stem 110. The injector line 100 is interconnected with a passage 120 opening into the upper portion 112 immediately adjacent the lower end of bushing 114 and the lower end of the intermediate portion 116 terminates in a plurality of ports 122 that are arranged to direct streams of fuel into the charge as it flows around the in take valve 22. It may thus be seen that during operation of the engine the fuel valve 74 will meter the fuel flow and the distributor 48 will deliver an increment of metered fuel to the chamber 118 formed by the intermediate portion 116 and the lower end of the upper The next time that the intake valve 22 opens and air is flowing into the combustion chamber, movement of the bushing 114 will force the metered fuel to be ejected through the ports 122 and thereby mixed with the air to form a combustible mixture of air and fuel.

It has been found that under some circumstances the high induction vacuum occuring around the valve guide 104 may tend to draw the fuel through the ports 122 even though the intake valve 22 is closed. Accordingly, the embodiment in Figure 3 may be employed. In this embodiment the intake valve 22 and its guide 104 are essentially. identical to the corresponding parts in the first embodiment. However, the lower end of the bushing 126 extends down into the intermediate portion 116 and includes an enlarged head 124 that is a close sliding fit on the surface of this portion 116. When the intake valve 22 is closed the enlarged head 124 will cover and close the ports 122. The high intake vacuum will thus be blocked from entering ports 122 and as a result the fuel anterior thereto will be isolated from the effects thereof. However, as soon as the intake valve 22 commences to open the head 124 will uncover the ports 122. As a result the further downward movement of the bushing 126 will pump the fuel from the chamber 118 and force it to be discharged from the intake ports 122.

The claims:

1. In an internal combustion engine having a combustion chamber with an intake valve for controlling the admission of induction air into said chamber, a fuel charge forming means including a fuel system and an induction system, said induction system including an intake passage forming an intake valve seat opening into said combustion chamber and an intake valve having an enlarged head disposed on said seat and a stem reciprocably disposed in a valve guide, a pump chamber formed by said stem and guide and plunger means movable with said stem through said chamber for forcing the contents thereof out of said chamber and into the charge flowing through said intake passage during opening movement of said valve, said fuel system being responsive to the air flow through said induction system and effective to deliver metered quantities of fuel to said pump chamber.

5. Charge forming means for an internal combustion engine having at least one combustion chamber, said means comprising a fuel system and an induction system, said induction system having an intake passage communicating with said combustion chamber and forming an intake valve seat in one side thereof, a valve guide having an axial passage therethrough in substantial alignment with said seat, a valve having an enlarged head disposed in said seat and having a stem reciprocably disposed in said guide passage, said stem and guide passage being spaced to form a pumping chamber therebetween, said pumping chamber including an inlet and outlet ports opening into said intake passage, plunger 1 means disposed in said chamber and movable with said stem for pumping fuel from said chamber through said ports and into said intake passage during opening movement of said intake valve, said fuel means being responsive to the air flow through said induction system and interconnected with the inlet to said chamber for delivering metered quantities of fuel to said chamber.

6. In an engine having a combustion chamber with an intake passage opening into said chamber and forming an intake valve seat, an intake valve having a head disposed on said seat and a stem reciprocably disposed in a guide member, said stem and guide forming a chamber having a plurality of outlet ports directed toward said seat, a bushing on said valve stem movable therewith in said guide and adapted to form a pump plunger,

said bushing being adapted to pump metered quantities p ump located adjacent said intake valve and actuated v by reciprocating movement thereof, a fuel system having means for metering fuel and delivering said metered fuel to said pump.

2. In an internal combustion engine having a combustion chamber, an intake valve having an enlarged head controlling an opening into said chamber and a stem reciprocably disposed in a valve guide, a pump formed by said stem and adapted to pump metered quantities of fuel into the charge flowing through said opening during opening movement of said intake valve.

3. In an internal combustion engine having a combustion chamber with an intake valve seat opening thereinto, a valve guide having a passage therethrough in substantial alignment with said seat, an intake valve the stem thereof reciprocably disposed in said passage and having an enlarged head disposed in said seat for controlling the fiow of .air into said chamber, at least a portion of said stem being spaced from the surface of said passage to form a chamber therebetween having an inlet adapted to be interconnected with a source of fuel and having outlet ports directed in the general direction of said enlarged head, said stem including plunger means disposed in said chamber and movable with said valve for discharging the contents of said chamber through said ports during opening movement' of said valve.

4 Charge forming means for an internal combustion engine having at least one combustion chamber, said of fuel into said intake passage during opening movement of said intake valve.

7. An intake valve assembly for an internal combustion engine having a combustion chamber with an intake valve seat opening thereinto, said assembly comprising a valve guide having an axial passage therethrough, a poppet valve having a stem reciprocably disposed in said axial passage and a head adapted to be disposed in said seat, a bushing on said stem disposed in said chamber and movable with said stem, said bushing forming a pump plunger for discharging metered fuel from said chamber.

8. An intake valve assembly for an internal combusa tion engine having a combustion chamber with an intake valve seat opening thereinto, said assembly comprising a valve guide having an axial passage therethrough with a portion of different diameters, a poppet valve having a stem disposed in said passage with a section thereof in sliding engagement with a portion of said passage of reduced diameter, a bushing secured to said valve stem and movable therewith disposed in a portion of said passage of enlarged diameter and in sliding engagement with the surface thereof, said bushing forming a pumping plunger in said chamber for forcing the contents of 5 11. The combination of claim 8 wherein said bushing 2,033,211 includes a portion adapted to close said ports when said 2,157 034 intake valve is in the closed position. 2,793,628 2,809,621

References Cited in the file of this patent UNITED STATES PATENTS 1,799,397 Taylor et 211. .i Apr. 7, 1931 6 Tice Mar. 10, 1936 Tice May 2, 1939 Floyd May 28, 1957 Layne .g Oct. 15, 1957 

